Is it a yosh thing? I cant think of any aikikai folks who have not used women as uke. I dont get out of te house much, though.
Sensei has been in the Aikikai for nearly forty years! His pickiness about his ukes started about fifteen years ago, and it's definitely nothing to do with his Yoshinkan origins.
The only Aikikai teacher I have heard of who has an actual policy of not practising with women (actually I gather he doesn't even allow women as members in his dojo) is in Florida. He is quite clear about his reasons - whether anyone else agrees or disagrees with them is apparently not something that bothers him.